Who is the real John McAfee? He's the man who went on the run after his neighbour was found dead, face-up, with a bullet in his head. He's the man who jump-started the multibillion-dollar anti-virus industry. And now he thinks he can make you invisible on the internet.

Within tech circles he's long been a legend. But for most people, McAfee came to prominence last year when he fled his Central American home - teeth stained, hair dyed, in disguise - rather than let himself be questioned by authorities he accused of being corrupt.

He tells the BBC he had "no connection whatsoever" with his neighbour's death. Police say he remains a "person of interest".

Back in the US, after posting footage of young female "friends" stroking his naked tattooed torso, he now plans to neutralise the NSA's cyber-surveillance system.

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John McAfee returned to the US last December after being released from a Guatemalan jail

"I've been called paranoid, schizophrenic, the wild child of Silicon Valley," McAfee acknowledges.

But he has a different perspective: "I'm an entrepreneur. I always have been. I am curious and I enjoy solving problems.

"I think that it's when we step out of the road, step outside the box, become our own person and we walk fearlessly down paths other people wouldn't look at, that true progress comes. And sometimes true beauty as well.

"We're missing that. We're missing the people who have the courage to walk into the wilderness just to see what's there."

This is how Amy Emshwiller, the teenage ex-prostitute he lived with in Belize, describes him: "He's sweet, generous. He likes to like adventures. He's serious and usually he has a dark sense of humour. He's generally a sweet guy. He just doesn't like to be [expletive] with."

So, who is the real John McAfee?

To have any chance of knowing and gaining an informed opinion of what really motivated his erratic-sounding behaviour after the killing of Gregory Faull, you must travel deep into the 68-year-old's past.

Addicted and expelled

Despite his Southern accent, the bleached-blond and goateed businessman is in fact half-British - the son of an Englishwoman who met an American soldier stationed in the UK during World War II.

When she tried to shoot me in the head, what I saw was a frightened child. I'm deaf in one ear now, but I don't have a bullet in my headJohn McAfee

"I feel as much British as I do American," McAfee says. "There's not much difference between our countries."

They moved to Virginia when he was young, where he had a troubled childhood. His father was an abusive alcoholic who, when McAfee was aged 15, shot himself dead. In the following years, McAfee says, he too began drinking heavily and taking drugs, but still managed to maintain a promising academic career.

That came to an end in the late 1960s when Northeast State Louisiana State College terminated his PhD in mathematics after it was revealed that he had slept with an undergraduate he was mentoring.

They later married and McAfee turned his skills to a series of programming jobs with some of the biggest tech organisations of the time including Nasa, General Electric, Siemens, Univac and Xerox, all the while continuing to indulge in his addictions.

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John McAfee played up to his bad boy reputation in a video he uploaded in June

"Most of my bosses also used drugs of some kind," he says. "I was in the tech field, after all, we were the leading edge in technology and the leading age in personal experimentation.

"I had to hide it from my mother and sometimes from my wife. But in the work environment - depending on where you worked - in some companies drugs were taken openly at lunchtime in people's offices. It was a bizarre time."

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McAfee says he has never used anti-virus software

Matters came to a head in the early 1980s after his wife left him, his most recent employer, Omex, let him go and the scale of his drug dependency forced him to seek help.

"It was 1984, the last time that I took drugs, drank alcohol or sold drugs for that matter," he says.

"I simply stopped. I started going to an organisation called Alcoholics Anonymous... and that was my last taste of that world.

"However, it is still with me. My body is covered with tattoos from that period. And I'm afraid some of my ideas and concepts and attitudes that were moulded during that time are still with me. That's why people think, perhaps, I'm a little bit off the wall."

Anti-virus millionaire

Despite his troubles, McAfee managed to land a job at defence contractor Lockheed Martin, where he worked on a classified voice-recognition program.

There he came across an unusual bit of self-replicating code designed to copy itself on to any floppy disk inserted into affected computers. When examined, it contained the message: "Welcome to the dungeon. Beware of this VIRUS."

"When I first read about the Pakistani Brain virus, I'd never heard of a virus before, neither had anyone in technology," remembers McAfee. "It fascinated me."

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Media captionJohn McAfee speaks to Leo Kelion about his life and why he fled from the police in Belize

He worked out a way to disinfect the computers and then spread the cure via the bulletin board system, a precursor to the web.

The challenge inspired him to set up a business of his own: McAfee Associates - a firm that would later be sold, years after he had left, to Intel for more than $7.6bn (£4.7bn).

"I knew the field would become extremely large because people being who they are, there will always be hackers," he says.

"There's always going to be someone who likes you and someone who dislikes you. Someone who thinks you're a hero and some that think you're a villainJohn McAfee

"It's why we have graffiti on the walls of the inner city. People like to deface things. They like to disrupt things.

"So, given that fact, computer viruses were not going to go away and were only going to get worse. I just did what I could to be at the forefront of that industry for as long as I could."

Despite this, he says, he has never himself used any of the products made by the firm that continues to bear his name.

"I'm constantly under attack, yet I use no software protection.

"I protect myself by constantly changing my IP [internet protocol] address, by not attaching my name to any device I use, and by not going on to sites where you might pick up a virus.

"Porn sites, for example, I just don't go there.

"Secondly, I practise safe computing. If someone sends me an email with a link, I'm not going there until I can call the person to verify that they sent me the email.

"It sounds absurd to live that way, but I would rather trust my own devices and thoughts than someone else's software."

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John McAfee says he has not taken drugs or drunk alcohol for nearly three decades

After selling his stake in the business in 1994, McAfee went on to found and sell other companies, including an instant messaging system, a firewall provider and a ranch from which he offered flights in "trikes" - low-flying, engine-powered cabins suspended from hang-gliders.

Then he headed south.

Research and raid

In 2008, at an age others might be thinking of putting up their feet, McAfee moved to the jungle of Belize with the stated intention of trying to cure another kind of infection.

"I came across a concept called quorum sensing, which is the technique that bacteria use to communicate with each other.

"Up until about 10 years ago we didn't even know that bacteria did communicate, but we find out they have a very sophisticated communication system. I wanted to explore and investigate that to see if we could come up with new antibiotics."

He picked the area, he says, because the plants that grew along the country's Rio Nuevo river contained compounds that inhibit bacteria from sending chemical signals to each other and thus thwart their ability to co-ordinate an attack.

Things didn't go as planned.

The first sign of trouble was when journalists invited to his Carmelita, Orange Walk, base wrote stories that made clear they did not know what to make of the operation.

Then a falling-out with the microbiologist he was working with, Allison Adonizio, put the project at risk when she quit.

Dr Adonizio, who is now based in Philadelphia, did not want to be interviewed.

In April 2012, matters came to a head when the Belize police force's Gang Suppression Unit raided the research facility.

McAfee says the officers claimed they suspected it was being used to make the illegal psycho-stimulant methamphetamine.

They shot his dog, he says, confiscated both his passport and licensed weapons on the property, and briefly imprisoned him before dropping the charges.

"Under no circumstances did they really believe it was a meth lab," he states.

"Everybody knew it was a biotech lab because I had hired half of the people in the village to work there. They all knew what I was doing.

The Belize Times - published by the leading opposition party - suggested the "barbaric assault" on McAfee was a "global black eye" for the nation and a threat to its tourist industry.

"I do wish that I were smarter socially," reflects McAfee.

"I think I have the ability to solve mathematical equations and programming issues very easily, but I am a little bit naive in some social situations. And certainly in Belize I was way naive."

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Amy Emshwiller moved with John McAfee to the Caribbean town of San Pedro

At the time of the raid, McAfee had begun an affair with a 16-year-old ex-prostitute he had met on Belize Independence Day.

"I was partying, I was drinking, and I went into this bar and the owner said a friend wants to meet me and likes me," remembers Amy Emshwiller, who still lives in Belize.

"[He said] can I have your number, and then two weeks later he called me."

She says he was unaware she was less than a quarter of his age.

"He didn't know how old I was. I lied to him saying I was 18, and he thought it was OK.

I didn't quite realise that his lifestyle would be this older guy surrounded by young girls and bodyguards with gunsChad Essley, Graphic novelist

"I let him fall in love first before I told him my age.

"When I told him he was so [expletive] shocked that he didn't know what to do. He was baffled. And he was like: 'I still love you, I don't know what to do. I'm in love with a young girl.' That's how that happened."

McAfee's long-term American girlfriend left him. And like many things in his life, the new affair proved complicated.

One night Emshwiller took McAfee's gun. She aimed it at his head, squeezed her eyes shut and pulled the trigger. She missed.

He continued the relationship.

"Amy, for one - and many girls in Belize - has a horrific story of abuse that if I told you, you could not believe it," McAfee explains.

"Of course she's not going to be well. Of course she's going to have issues.

"When she tried to shoot me in the head what I saw was a frightened child.

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After the raid on his Carmelita property, McAfee moved to San Pedro on Ambergris Caye island

"What I saw was a confused girl who had been so abused - physically, sexually, emotionally - beyond any description.

"What are you going to do? Throw her out? That doesn't help her.

"All she did was burst my eardrum. I'm deaf in one ear now, but I don't have a bullet in my head. Forgiveness is one of the graces that we have as human beings. Can I be faulted for indulging in it?"

Emshwiller confirms the event but says she wanted to scare, not kill, him after he had said he wanted another girl. She adds it was not the only such incident provoked by her jealousy.

"One time before, I held him in the corner and I put a knife at his throat," she says.

"And he just said: 'Go ahead. Kill me.' And I couldn't do it. I just dropped the knife and walked out."

Image caption
Cartoonist Chad Essley is working on a graphic novel about McAfee which is due for release next year

Following the raid, McAfee and Emshwiller moved to his villa at San Pedro - a town on Belize's biggest island, Ambergris Caye - where they agreed to have an open relationship.

There they were visited by Chad Essley, a cartoonist, who began collaborating on a book about McAfee's life.

"I didn't quite realise that his lifestyle would be this older guy surrounded by young girls and bodyguards with guns," he says.

"Many of these girls were former prostitutes or had very rough lives.

"It was expressly forbidden to go out in the town and drink - the smell of alcohol, he could not be around it. He didn't want any of the girls doing any drugs at all.

"I interviewed each of these girls, got their background. They were incredibly sad. They were definitely in a better sort of situation being around John."

Meanwhile next door, Gregory Faull, an Orlando sports bar owner who had recently divorced and decided to live in his Belize holiday home, was becoming increasingly irate at his neighbour's activities.

'Hatchet buried'

On Thursday, 8 November 2012, McAfee made the local headlines when he donated 40 stun guns, handcuffs and batons to the local police at a press conference.

Mayor Daniel Guerrero thanked him, stating: "Crime is affecting the tourism industry as we have been listed on travel advisories; it is time to stop this. Let us protect our industry and turn San Pedro into the safe haven once more."

That night the local TV bulletin declared that "the hatchet was formally buried", suggesting the rift between McAfee and Belize's authorities had ended.

Early on Sunday morning, Mr Faull was found dead in a pool of his blood by his housekeeper. Police called to the scene found a single 9mm shell nearby. They said a mobile phone and laptop were missing but there were no visible signs of a forced entry.

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Gregory Faull was found shot dead at his home in Belize

The head of the police's Gang Suppression Unit told a local newspaper that his officers wanted to speak to McAfee as part of the investigation, but when they called at his house he did not appear to be in.

An article posted the following day by Wired magazine revealed why.

McAfee told the publication he had seen the officers approaching and had hidden in the sand of his property putting a cardboard box over his head.

He recalls that his caretaker had told him of Mr Faull's murder, and now he feared for his own life.

"The first thing that came to my mind was, 'Oh, my Lord. The government is finally trying to rid themselves of me,' he says.

"The government does from time to time.

"I had certainly been a huge thorn in their side, and they had simply got the wrong white man.

"Seriously, this is what went through my mind. My friends sort of calmed me down, and later said that's absurd. At the time I did not think so."

McAfee acknowledges that he and Mr Faull had been at odds, but plays down the idea they hated each other or that he suspected him of being the person who had fed two of Emshwiller's dogs a poisoned tortilla.

"The entire five years I was there, I'd said maybe 15 words to him," he says.

"He did not like my dogs and the past two occasions I had seen him walking on the beach he complained. But so did everybody.

"There was no ongoing argument. Yeah, he was mad about my dogs. Maybe as I'm beginning to think now, maybe he was the one who poisoned them. At the time I certainly did not believe that."

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John McAfee dyed his hair black as part of one of his disguises

In fact, as ABC News later revealed, Mr Faull had filed a complaint to Mayor Guerrero about McAfee the previous month.

It said McAfee's dog had attacked a tourist; that his security guards had "terrified" other residents by walking around with shotguns and shining lights in their eyes, and that taxis and other traffic had been arriving at his property "at all hours", causing a disturbance.

"I did not find that out until weeks after I came back to the States," says McAfee when pressed about this.

"Belize is not like America where you file a complaint and then the police come out and chase things out. You file a complaint and it goes into a drawer."

Hiding out

McAfee then went on the run, saying he feared he would be "silenced" if he was caught and thrown in jail.

It made headlines worldwide, in no small part due to the fact that he was posting updates to a blog and giving frequent interviews - actions he says were designed to ensure he couldn't be made to disappear if he had been caught.

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Prime Minister Dean Barrow said it was "utter and complete nonsense" that the police wanted to kill McAfee

"I disguised myself as a ragged salesman," he recalls.

"All it takes is some dirty clothes and not bathing for a few days and not combing my hair.

"You know, people saw my photograph everywhere because all of the police and army had it for that month and a half I was underground. I just made sure I looked different than that."

Questioned about the affair, Dean Barrow, Belize's prime minister, made it clear McAfee was not an official murder suspect, and had only been classed instead a "person of interest".

"I don't want to be unkind to the gentleman, but I believe he is extremely paranoid, even bonkers," the politician added.

Belize and corruption

The BBC put Mr McAfee's claims of corruption to the Belize government, which is currently embroiled in a scandal involving the issue of a passport to a South Korean man who had never visited the country.

It sent this reply:

Belize has made great strides in improving transparency and ethical behaviour across all government departments.

Where any sniff of corruption and evidence of such has been proven, the prime minister and the government have moved swiftly to stamp it out.

This has most recently been demonstrated by the sacking of the junior minister of immigration.

The US government and the Commonwealth have been instrumental in supporting Belize in addressing governance issues as we work to reduce even the appearance of fraud and corruption.

Corruption is a cancer that Belize will continue to correct - it has no place in government or in any public office and we do not and will not tolerate it.

The past is the past and this Belize government cannot change the behaviour of previous administrations or officials, but the prime minister has vowed to root out corruption wherever and whenever it occurs.

During this time McAfee continued to see Emshwiller.

"When he was on the run I went for lunches with him and then he would call and say: 'Come to this place, or go there,' she recalls.

"How to come, when to come. Not to go out, or stay home, or go to a different location. He would tell me that so nobody would get me."

She adds that she regrets she did not go with him when he finally decided to escape the country.

The next major development came on 3 December when a reporter and photographer from Vice magazine revealed they were documenting McAfee's life on the run.

In what proved a frustrating twist for the tech guru, they then unwittingly revealed he had crossed the border to Guatemala - a fact revealed by a photo uploaded to the Vice website by staff at its headquarters, who failed to wipe its location data.

"I had gone out of my way to arrange the escape and I was breathing easily and looking forward to a few days of relaxation," remembers McAfee.

"We immediately had to go on the run again because we were in Guatemala illegally at this point. But it was no-one's real fault. It was just the fault of the moment."

A few days later McAfee was arrested. There was initially speculation he would be sent back to Belize, but a week later he was allowed to fly to Miami a free man.

"After it was over I asked myself, 'Good Lord, I must have been afraid,'" he says.

"But I really can't remember. I remember merely trying to solve the problems that occurred as they occurred."

Hero and villain

McAfee has offered a $25,000 bounty for information relating to Mr Faull's death, but says an attempt to contact the victim's family proved unsuccessful.

The family has called the reward a "hollow gesture" and suggested if McAfee really wanted to help he would have met with the Belize police.

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John McAfee continued to give interviews even when being held by the Guatemalan authorities

A spokesman for the country's government said its authorities still wanted to speak to the businessman.

"Mr McAfee's claims and his behaviour have been extreme," he told the BBC.

"The investigation is ongoing and McAfee remains a person of interest. If McAfee were to respond to questioning it would make a difference to the progress of the investigation - but this is currently out of the hands of the government of Belize."

So long as the crime remains unsolved, it is inevitable the entrepreneur will always face suspicion. But he says he can live with that.

"There's always going to be someone who likes you and someone who dislikes you," he says.

"Someone who thinks you're a hero and some that think you're a villain. You know I just do what I can in situations like this to continue to state that I'm totally innocent."

That doesn't mean he is trying to forget his time in Belize.

In addition to the graphic novel, he is working with a Canadian firm to make both a documentary and a movie about his time there.

He adds that George Jung - the imprisoned cocaine drugs lord portrayed by Johnny Depp in the film Blow - has been picked to write his biography.

While those projects brew, McAfee has returned to Silicon Valley, announcing the forthcoming launch of a $100 gadget that he promises can make you invisible on the net.

"If you cannot see it, you cannot hack it, you cannot look at it, you cannot spy on anything happening inside it," he explains.

He says the D-Central units will fit in people's pockets and allow their phones, tablets and PCs to communicate with other owners' devices within a three-block radius.

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John McAfee is working with a Canadian company to make a documentary about his life

He adds they can also connect to the net anonymously via a node - a separate piece of equipment attached to the network - either directly or with their encrypted data relayed relayed via other D-Central boxes.

Each will frequently change their network identifier - a long number used by devices as an ID - making them hard to track, he explains.

He suggests it will appeal to college students who want to copy music anonymously and to businesses wanting to prevent the theft of corporate secrets.

He's also well aware that in the light of Edward Snowden's leaks about surveillance techniques used by the US and UK governments, part of the appeal will be thwarting their efforts.

"You know from their own paranoia and desire to stay in power, they are watching everything they can," he says.

Will the tech work? Will he really frustrate the authorities once again?

At this point, like so much of John McAfee's life, it's impossible to be sure of all the facts and it's ultimately up to you whether you take him at his word.